Screw driver



Nov. 24 1925- c. A. BEARDMORE scREw DRIVER' Filed Dec. 28, 1923 gnom/Lfoz Patented Nov.` i 24, A

UNITEDv STATES CLARENCE ALBERT BEARDHOBE, 0F ANN'APOLIB, IARYLAND.

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Application med December as, 192s. serial no. 083,232.

To all whom t 'may concern:

Be it known that I, CLARENCE A. BEAR!)- MoRE, a citizen of the United States, residing at Annapolis, in the county of Anne Arundel and State of Maryland, have inventedy certain new and useful Improvements in a Screw Driver, of which the following is a specification. l v

This invention relates to improvements 1n screw drivers.

The primary object of this invention is the provision of a screw driver which embodies novel means for holding the screw prior to and during the screw driving operation.

A further object of this invention is the provisionlof a novel type of screw driver embodying a bit which has a spllt screw lrerf inserting end, and novel means to expand the screw kerf inserting end so that a screw or other element may be supported by the screw drivery bit prior to and during the screw inserting operation.

Other objects and advantages of this 1n- 'vention will be apparent' during the course of the following detailed description. p

In the accompanying drawing, forming a part of this specification, and wherein similar reference characters designate corresponding parts throughout the several i views,

Figure 1 is a side elevation of the improved screw driver, showin the blade ends of the bit thereof in expan ed relation for supporting a screw.

Fig. 2 is a fragmentary enlarged cross sectional view taken through cooperating details of the improved screw driver, showing the same holding a screw.

- Fig.. 3 is a cross sectional View taken" bodiment of this invention the letter Av may generally designate the improved screw driver, which consists of a handle construction B; bit C; and means D Afor regulating the bit C so that the same of itself may support a screw element. v

In the drawing the handle construction B lsshown as consisting of a hollowshank or casing portion 15, which provides a socket or assageway 17 longitudinally therethroug opening inwardly from the lower 'tapered end 18 of the same. The shank v15 at the end 18 is internally screw threaded on a taper. Atpits upper end the shank or casing portion 15 has a solid extension 18 adapted to receive the hand engaging member 19 thereon, which may be connected thereto in any approved manner, as by a ferrule 20. Just below the ferrule 20,-the shank or casing 15 is provided with an annular screw threaded extension 25 yadapted to adjustably receive a nut member 26 which forms a part of the bit regulating means D, and as will be subsequently vdescribed.

The bit C of the'screw driver is of novel construction, and includes a hollow clyin- -drical shaped body portion 30 which is provided wit an externally tapered screw threaded end 31 at the top thereof. The bit C furthermore includes the similarly formed and shaped lat blades or jaws 32 and 33 integrally connected with the body portion 30, and extending downwardly from the body portion 30 in a converging relation. The blades 32 and 33 are so formed upon the body portion 30 that the resilient tendency of the same is to en age each other at the outer or screw ker inserting ends thereof. These blades 32 and 33 are, of course, formed by longitudinally splitting the bit C inwardly from the chisel end thereof. As can be seen from Figure 5 of the drawing the blades 32 and 33 are tapered from their juncture-with the bod portion 30 to their relatively engaging ree ends, where they provide a chisel edge for engaging in the screw kerf. The body portion 30 of' the bit'C is provided with a passageway or bore 37 therethrough, which terminates intermediate the ends of the bit C on the beveled seat or seats 38 provided on the facing sides ofA the blades 32 and 33 adjacent their juncture with the body portion 30.

The bit C is adapted to be insertedA at its ,screw threaded end 31 in the screw threaded socket at the lower end of the hollow shank 15, substantially as is illustrated in the drawing, and thus the bit C is fiXedly con'- nected with the handle construction B.

Referring to the means D for expanding the bitJ blades or jaws 32 and 33, the same preferably comprises a solid substantially cylindrical shaped pin or expanding member 40, which is slidably disposed through the aligning bores or openings 17 and 37.0f the casings l and 30 respectively. At Iits lower end the pin 40 provides a tapered point 42 which normally seats on the seating surfaces 38 of the blades 32 and 33. The nut 26 is adjustable on the screw threaded portion 25 of the handle casing or shank l5, and may 'by such adjustment be moved longitudinally of the screw driver. This nut 26 is of peculiar formation, providing a depending flange 45 at the outer edge thereof, which forms an open recess 46 facing toward the bit end of the screw driver. A movable cross pin or member 47 is carried by the casing l5 of the handle construction li; `being transversely disposed through aligning openings 49 which are provided through the casing 15 within the area of the recess 4G, so that the ends of this pin or member 47 extend outwardly from the casing 15 into the recess 46. The pin or member 47 cannot become detached from the screw driver, because of the impedance offered by the annular depending flange 45. Upon adjustment of the'nt 26 the pin 47 may be moved longitudinally within the screw driver casing l5, since the openings 49 are of sufficient elongation to permit such movement of the pin 47.

A spiral spring 50 is preferably provided within thebore orpassageway 17 of the handle casing 15, at its lower end preferably resting upon and engaging the upper edge of the bit, C, and at its upper end having a transverse portion or convolution thereof extending through a suitable opening provided transversely of the expanding pin 40. This spring 50 is normally under compression and urges the expanding member 40 so that the top edge or margin 52 thereof engages the circumference of the transverse pin 47.A

Referring to the operation of the improved screw driver, it is to be particularly noted that the bit blades 32 and 33 are a part of the bit C, and they alone engage lin the screw kerf for the transmission of power or force to effect the screw driving operation. The normal and inherent tendency of these blades 32 and 33 is to move towardeach other so that the chisel edge of the bit C is always in position to be inserted in the screw kerf. Having been inserted in the screw kerf, in order to move the jaws or blades 32 and 33 so that they will engage the side edges `of the kerf for supporting the screw independent of manual aid, it is merely necessary for the operator to move means/1 the nut 26 for a rotation or part `of a rotation upon `the shank or casing 15. The nut 26 incident to such rotation will descend, and the bottom surface of the recess 46 will engage the outwardly extending ends of the pin 47 and-move the pin 47 down wardly within the openings 49. rlhis movement of the pin 47 will, of course, push the expanding pin 40 downwardly within the screw driver, and against the normal action of the spring 50. The tapered end 42 of the member 40 will thus engage on the beveled seats 38 of the blades 32 and 33, and will expand `the bit C at its screw `kerf inserting end, by `moving the blades 32 and 33 away from each other until their screw kerf inserting ends are expanded into engagement with the side walls of the screw kerf, and will clamp the screw into a supported relation with the bit, as

can readily be understood. This expanding action upon the bit blades is effected at a point considerably remote from the screw, thus retaining the resiliency of the blades 32 and 33. It is very apparent that very little movement of the nut 2G is necessary to effect the expanding movement sufficient to clamp the screw to the bit, and there will be no liability of injury to the bit blades because of the fact that unnecessary expanding action thereof is prevented by reason of the limitation. of movement of the pin 47 within its openings 49 of the casing 15.

From the foregoing description of this invention it is apparent that a screw driver has been provided which is of a relatively simple nature, and which may be economically produced to perform the function of holding the screw incident to the driving operation. The bit C is lixedly connected to the handle construction of thc screw driver, and is not movable rotationally or longitudinally with respect thereto. YThis is au important feature. lVliile screw threaded connection between the casing l5 and the bit C has been shown, such connection is not necessary in all instances, since a welded connection may be provided in lieu thereof. It is to be particularly" noted that the screw shank C directly bears all of the strain incident to the screw driving or removing operation, and the blades 32 and 33 in addition to providing the means for supporting the screw are so arranged with respect to the expanding means as to be of sufficient strength to directly withstand all torsional strains coming thereon.

Various changes in the shape, size, and arrangement of parts may be made to the form of the invention herein shown and described, without departing from the spirit of this invention or the` scope of the claims.

I claim:

l. A screw driver comprising a handle construction including a hollow shank7 a nut adj ustably carried by said hollow shank, said hollow shank at the upper end thereof having a pair of elongated aligning apertures therethrough,y a pin carried by said easing within said apertures so that said pin may be moved longitudinally of the screw driver upon adjustment of the nut into engagement therewith, a bit including a pair of resiliently mounted blades, a member slidable within said bit and within said hollow easing, andspring means normally urging said member into engagement with the nut adjusting pin, said member upon adjustment of said nut adapted to be moved by engagement of said pin therewith to expand said bit blades.

2. A screw driver comprising a bit including a pair of blades which at their screw engaging ends are normally urged 1nto 1nherently engaged relation, a p1n member slidable longitudinally within a passageway provided through said bit, a cross pin movably carried by said bit for sliding longitudinally of the bit into cooperating relation with said pin, and a nut vadjustable longitudinally of said bit for engaging said eross pin upon movement of the nut toward the blades whereby to force the same longitudinally of the bit into'engageuient with said first mentioned pin to move the latter into engagement with the blades for relatively expanding them at their screw engaging ends.

P. A. screwdriver comprising a handle eimstruetion including a hollow shank, a lnut adjustably carried by said hollow shank, said hollow shank at the upper end thereof having a pair of elongated aligning apertures therethrough, a pin carried by said casing within said apertures so that said pin' may be moved longitudinally of the screw driver upon adjustment of the nut into engagement therewith, a bit including a pair of resiliently carried blades, a member slidable within said bit'into engagement with said blades and within said hollow shank, said member upon adjustment of the nut adapted to be moved by engagement of said pin therewith to expand said bit blades.

'4. In a screw driver a handle providing a body construction with a central passageway therethrough and having a pair of bit blades. connected therewith in inherent resiliently urged engagement at their screw a nut adj ust'abl y threaded on the body eon-.

struction in engagement with said cross pin for sliding the latter longitudinally of the screw driver when the nut is rotated in adjustment toward the blades of the screw driver whereby to force the pin along the passageway of said body construction into engagement with said blades to expand the saule at their serew operating ends.

CLARENCE ALBERT BEARDMDRE. 

